Black beans are another example. There are various brands available here. The expensive ones had more/all beans that were black in colour while the cheaper, par

Black beans are another example. There are various brands available here. The expensive ones had more/all beans that were black in colour while the cheaper, particularly store brands, were all dark brown. Presumably there are different grades of beans so the price of the can was a predictor of the colour of the contents. Now when you open a can, regardless of brand, they are almost universally dark brown.